help soldering lipo pack tabs?

They are either nickel which plumbers flux will do, or aluminium, which needs a very special flux.

Use some sandpaper to scratch through the top layer of plating on the tabs. This will help the solder adhere to the metal. If, when you scratch it, the base color is gold, it's probably nickel plate over brass rather than stainless.

If the really are stainless, it's often best (read that as safer) to take them to somewhere to have them spot-welded rather than solder them.

-- Ray

"Mike @ zen" > wrote

I use the paste flux with the solder in it; called tinning flux. I also use solder with 2% silver, and lead in it. I have found plumbers "no lead" solder is much harder to make stick without a longer heat application. (bad thing)

I get the wire hot and tinned, with an extra small blob of solder on it, flux already applied to the battery (small amount, and stay away from the edges where the vents are) and once the solder on the wire is hot, apply it and the iron to the battery, until the flux is about stopped bubbling,and the solder flows, then take the heat away, wait for it to solidify without moving it (and getting a "cold, crystalline" joint), then as soon as it hardens, quickly put a wet rag or sponge on it, to cool down the battery as fast as possible.

I know, you are not supposed to solder non tabbed cells, but who doesn't!

I see now, you are soldering tabs. All my advice will still hold true, but a scratch or two with some fine sandpaper may help, if trying it without does not work.

It probably will be OK without the sandpaper treatment.

refer to RCGroups "Help soldering a123 cells w/o tabs"

Regards Alan T. Alan's Hobby Model & RC FAQ Web Links

Thanks.. I am shore thay are alumiunm tab now as I have tryed every flux and solder now ....last thing to try ...any idear where to get some alumiunm flux

Tanic pacs.com has it.

Art

Otherwise google Carrs BLUE flux - for nearest stockist. I got some at a model railway place in the UK.

Watch out for fumes..make you ill for a day or so if you breathe too much in.

OOPS. It's tanicpacks.com. No space.